The invention relates to a process and apparatus for the removal or controlled reduction of adhesive films of liquid on hard surfaces, especially for the removal or dosing of rolling liquid used in a cold-rolling process.
In various technical fields such as cold-rolling, a film of liquid is employed to carry out certain operating processes such as the natural rolling process on the surface of the goods that are to be processed, which film is subsequently to be either removed completely or else reduced to a controlled, dosed, thickness. Hitherto, wipers or squeezing rolls have been used for this purpose, or else the liquid, particularly oil, was removed by a mechanical process. The use of mechanical members, such as wipers and squeezing rolls, however, turns out to be insufficient with increasing relative speed between the surface and the mechanical members: at high speed, a kind of aquaplaning effect occurs which leads to the lifting off of the mechanical tools. In the case of chemical processes, it is a disadvantage that in that case, the liquid is lost so that such processes are expensive. Many times, such a complete removal as occurs in the case of chemical treatment, is not desirable at all; rather in many cases, a certain residual thickness of the liquid film is to be retained in a precisely distributed uniform thickness.
Moreover, special problems will occur, whenever the processing liquid is easily combustible and consequently may ignite by formation of sparks which can never be avoided, for example, in the case of running up of the edges during rolling.
It is an object of the present invention to provide a process of the type mentioned above as well as an apparatus to carry it out, which assures a controlled removal or a dosed reduction of arbitrary adherent films of liquid on hard surfaces even in the case of high relative speeds between the surface and the means serving for the removal with the simultaneous possibility of recapturing the removed liquid.